This invention relates generally to the provision of lightweight, fireproof roofing tiles, capable of withstanding foot traffic as well as wind up-lift forces, and more particularly concerns cementitious in admixtures from which such roofing pieces are formed.
There is continuous need for improvements in lightweight cementitious tiles, and their installation, for example to prevent breakage during such installation, and thereafter, and to prevent tile up-lift due to wind.
Standard concrete and clay roofing tiles are installed with the butt end supported by the preceding tile and the tail end resting on the roof surface or "hung" on a narrow wooden batten. This means that the tile is unsupported between these points and must, therefore be strong enough to withstand foot traffic. Tests require that the product support 300 lbs. This required the use of excessively heavy tiles. Also, tiles made of lightweight cementitious or other materials do not withstand wind up-lift forces as well as heavy tiles do.
Prior roofing tiles and methods of production are disclosed, for example, in Jakel U.S. Pat. Nos. 3,841,885, Jakel 3,870,777, Kirkhuff 3,852,934 and Murdock 4,288,959, and Wood 4,673,659 describing problems encountered in lightweight extruded tile production.